Various governmental and other agencies have a recognized requirement for self-contained breathing apparatus to support EOD, missile fuel handlers, firefighters, etc., in an oxygen deficient and sometimes toxic agent evironment. The breathing apparatus (hereinafter "BA") generally comprises an air cylinder or bottle strapped to the wearer's back. The cylinder supplies air to the wearer through a face mask connected thereto via a hose arrangement and regulator. The regulator is strapped to the wearer's waist and the hose arrangement extends upwardly from the regulator along the wearer's chest for connection to the face mask.
There are actually various commercially available BAs for civilian and military use and they may be somewhat physically different from each other although they are each generally designed with the aforesaid components to protect the wearer's respiratory system from toxic chemical vaporous atmospheres, such as those from toxic commercial chemicals as red fuming nitric acid (RFNA) and unsymmetrical dimethyl hydrazine (UDMH) and toxic chemical agents as VX, GB and GD.
However, the wearer is still subject to poisoning through the skin (i.e., percutaneous poisoning). In addition, the BA components are subject to attack by the chemicals such that deterioration and corrosion result. Furthermore, the wearer and their BA, once in any of the toxic chemical environments, becomes totally contaminated.